Director Katherine Murphy said: "How many times do the public need to keep hearing about this before the government is embarrassed enough to do something about it?

"The evidence was there but not acted on. That is completely unacceptable. The system of regulation and supervision needs to be urgently reformed."

The trust, which has two hospitals serving about 300,000 people, said it was "not complacent".

Chairman Michael Large said: “It is an extremely serious matter and we do not seek to underestimate its gravity.”

CQC chief executive Cynthia Bower said: “Our work has uncovered serious failings. The trust has high mortality rates for emergency admissions and we have found evidence of significant problems in different parts of the organisation.

"The trust has taken our concerns seriously but improvements are simply not happening fast enough.

"Our confidence in the management's ability to deliver on commitments and to turn the situation around has been severely dented.”

Monitor has also taken action against Colchester Hospital University NHS Foundation Trust for failing to improve standards and its chairman Richard Bourne has been removed.

Health Minister Mike O'Brien said patient safety must be a top priority for the NHS.

He added: “We expect these issues to be dealt with quickly and effectively to ensure high quality, safe care for patients.”